pub fn odd_fibnacci_sum(num: u32) -> u32 {
    let mut sum = 0;
    let mut a = 0;
    let mut b = 1;
    
    while b < num {
        // 如果当前斐波那契数是奇数，加入到总和中
        if b % 2 == 1 {
            sum += b;
        }
        
        // 计算下一个斐波那契数
        let temp = a + b;
        a = b;
        b = temp;
    }
    
    sum
}
